[30.03] ``Voice-prints" within the unstable light curves of GRS 1915+105: QPOs at 165 and 113 Hz

We have begun sorting the wildly varying light curves of GRS
1915+105 into binned intervals defined by the X-ray
intensity and spectral hardness, in order to isolate power
density spectra for different phases of the instability. A
portion of some "theta" type light curves (classification of
Belloni et al.) produces a QPO (and harmonics) at 165 (3)
Hz, while a portion of some "nu" type light curves produces
a QPO near 113 (3) Hz. These QPOs do not occur at the same
time, but they have nearly commensurate frequencies (3:2
ratio). These results support two conclusions. First, our
data selections suggest that the QPOs at 113 and 165 Hz
appear to be caused by the same mechanism that produces QPO
pairs in GRO J1655-40 (300, 450 Hz) and XTE J1550-564 (184,
276 Hz). Second, the results provide additional support for
the conjecture that fast X-ray QPOs in black hole binaries
represent some type of resonance condition rooted in general
relativity.